Electric signaling system for railways.



I. LAGROIX. ELECTRIC SIGNALING SYSTEM FOR RAILWAYS. APPLICATION FILED JAN. 24, 1907. BENBWEDNOV.6,'1908.

Patented June 15, 1909.

avwemtoz similar reference characters designate corre- UXITED STATES PATENT oFF oE. Y

FRED LAPROIX. OF SAN ANTONIO. TEXAS, ASFIGXOR, BY DIRECT AXD MESNE ASSIGNMENTS, T0 ELEWIRIVA L Al'll'UllA'llV RAILROAD SAFETY SIGX.- \L COMPANY, OF NEW YORK, N. Y.,

a ronromrrox or NEW i'o'RK.

ELECTRIC SIGNAILING SYSTEM FOR RAILWAYS.

Specification of Letters Patent.

Application filed January 24, 1907, Serial No. 353,824. Renewed November 6, 1908. Serial No. 461,385;

T eXas, have invented certain new and useful Improvements in Electric Signal Systems for Railways, of which the following is a specification.

' In the accompanying drawings, in which spending parts, 1" igure 1 is a diagrammatic view of the track circuits and connections.

.Fig. 2 is a similar view of the cab circuits and connections. I

ahead, an open switch, a broken rail, or other source of danger, he can locate the position of the obstruction.

It also has for its object the provision of means to enable the engineer in his cab to re-' ceive and to transmit signals from and to a distant point in the system.

Further, it has for its object other features which will be more particularly pointed out hereinafter.

This invention \,\IllSlSlS in the novel combination and arrangement of parts, such as will be hereinafter fully described and pointed out in the appended claims.

While the invention is particularly adapted to a single track road and will be described as so applied, yet it can be used depend u on-the nature of the road, the fre guency of trains, and other determining conitions. It has been, found that blocks of one mile in length meet the re uirements quite well. Therails of each lo'loc areeleo- .trically continuous and are separated irom the rails of the contiguous blodks by .the insulating breaks t. Interposedbetween the My inventionhas for its object the rovision of an electric signal system Where y the .ductor D to the track rail rails and electrically connected with the same is the battery B or other source of elec- I tricity, The rails of each blockare' connected by the wire I) which completes the circuit through the rails and the interposed battery.

- 11' each side of the track are the electric- Patented June 15, 1909. Y 1

In this wire are the magnets b on op osite sides of the track.

conductors C, D, extending parallel with the road. In each block the conductor C has a terminal in the switch 0 and asecond terminal 0 adjacent to said switch. Also ineach block the conductor D has a terminal in the switch (1 and adjacent 'to the' latter is a second terminal (1'. Leading from the conductor C is the 'branchwire 0 having a terminal o adjacent to the switch (1 and in this wire 1s the resistance coil 0. Another branch wire (Pleads fromthc conductor C to the contactrail 0. A branch wire (1 leads from thereonadjacent to the contact-rail.

When each block is in its normal condition that iswhen-the circuit is complete through the track rails, the battery B and themagnet b, the'latter will hold the switches 0,11,-

against the action of their springs. \Yhile so held the switch 0 makes contact with the tcr-,-

minal c andTthe switch dmakcs contact with the terminal cl; at the same time the switch (1 is out of contact with the terminal 0 At the end of the conductors (l, D, is the switch E, normally held open by a spring, for completing the circuit through the conductors at that point. Also in multiple connec tion with the conductors adjacent to the switch E is the magnet econtrolling .the switch c in the circuit leading through a battery and an electric bell. The switch 6 northrough the bell. Vfhcn the magnet becomes energized through the completion of the circuit through the conductors and a current "passing through the same the switch a is moved to closethe circuit and the bell is rung." Also in multiple connection with the ends'iof the eonductors'is the wire 6' included in the circuit of the telephone e p .Re'ferrin to Fig. 2 of the drawing, in the cab of the locomotive is a shunt-wound dynamo driven in any suitablemanner by The field power derived from the engine.

coils F of, the dynamo have a terminal f electrically connected with the wheel W ofthe 'inally is in a-position to break the circuit locomotive, and another terminal f in the yielding shoe S mounted on the engine in a position to engage with-the contact-rails c. A wire f 2 leads from the terminal wire f to the shoe S and has an electric contact as f 3 when said shoe is in a lowered position. In this wire f 2 is the resistance coil R." Inside of this wire f z is another wire f having. a multiple connection with the terminals of the field coils and in this wire is the switch for making and breaking the circuit through said wire. Inside of the wire f is another wire f 6 also in multiple connection with the terminal wires of the field coils. Interposed in the wire f is the telephone f 7 and also the switch f for controlling the passage of the current through said wire. In the circuit of the field coils is the normally closed switch f by means of which the said circuit can be inter-' ru ted.

n multiple connection with the armature coils A of thedynamo are the voltmeter H, the red lamp I, and the white lamp K. In series connection with the lamp I is the bell I; The red lam has a comparatively high resistance, and t m white lamp has a comparatively-low resistance. In the circuit of the lam I is the magnet 91 for moving the switch against the action of its spring to open the circuit through the lamp K. In the clrcuit of the lamp K is the magnet in for holding the switch Z against the action of its spring to open the circuit throu h the bell L.

The operation is as follows: The armature of the dynamo is constantly driven and the strength of the current generated by the armature of the dynamo and passing through the main circuit varies as the resistance in the circuit including the field coils varies. The

resistance of the circuit, including the field coils depends upon the length of the conductors O, D,'included in such circuit. If the circuitthrough the field coils and the conductors should be completed by the engage-v ment of the shoe S with a contact-rail c and the conductors electrically connected at should the electrical connection between the conductors be made close to the engine, then the resistance would be comparatively low. As the electrical connections between the conductors are made by obstructions of the track, the location of an obstruction would be ap roximated by theresistance indicators. Shou d the indicators show a high resistance, then itcould be concluded that the obstruction was at a considerable distance; if they should show a low resistance, then it would be inferred'that the obstruction was close at hand. I

When the shoe S is not in engagement with the contact-rail a the wire f normall completes the circuit through the field coils, but owing to the resistance R only a comparathat his apparatus is in working order.

K will cause the latter toglow witha very dull light, which will show to the engineer The passageof this comparatively weak current will also energize the magnet 73 suiliciently to hold the switch 1 open and thereby prevent the ringing of thebell L. This current, however, cannot pass through the red lamp I as the resistance ofthe latter is too great, consequently this lamp will not be lighted, nor will the bell I be rung; and the magneto will not be energized. The voltmeter II will indicate the passage of this comparatively weak current, which will also inform the engineer that his apparatus is in working order. If the lamp K should not glow and the voltmeter be inert the engineer would know that his apparatus was not in working order. To test all of his apparatus the engineer could complete the circuit through the wire f by closing the switch f and thereby cut out the. resistance R. This would allow the full strength of the current to pass through the circuit of the field coils and there would be a corresponding increase of voltage through the circuit of the armature coils.

This increase of current in the armature .1

through the red lamp I and the latter would also glow to its'maximum. The current passing through the circuit of the lampI would ring the bell I and energize the magnet 1'. and the latter would move the switch is to break the circuit through the lamp K. The interruption of this circuit would deenergize the magnet k and the latter would release the switch Z and the circuit through the bell'L would be established and said hell would ring. The interruption of the circuit through the lamp K would also extinguish the light in the latter.

As the engine moves along the shoe S sue eessively engages thecontact rails c and-by the signals transmittedthe engineer can ascertain the condition of the track. For an instance, suppose the locomotive is leaving block T and is entering block T, the depressed shoe will engage the. contact-rail e on the righthand side of the block T.

When this engagement takes place the terminalf of the field circuit will form an electrio' connection with the conductor D through the wheel W, thetrack on which the wheel rests,

and the wired. The other terminal f will form an electric connection with the conduc-.

tor C through the shoe S, the contact-rail c,

and the wire 0 If the road is in its normal condition, "with the circuit through the' con ductors C, D. incomplete, there will be no- (1 would be released and thecircuit of the conductor C would be broken at the contact c and-the circuit of the conductor D would be broken at the contact d. The circuit between the conductors would be established at the contact 0 by the engagement of the switch (1 with said contact. This completion of the circuit through the conductors C, D at the block T would also establish the circuit through the field coils of the dynamo and there would be a consequent-increase in the strength of the current passing through said field coils. This increase of current in the field coils would cause a corresponding increase in the current passing through the armature circuit. The increase of thecurrent in the armature circuit would cause the red lamp I to glow, the bells I and L to ring, and the white lamp K to cease to glow. These several signals would indicate to the engineer that there was an obstruction on the track ahead. By referring to the voltmeter H he can ascertain the location of the obstruction.

By calibrating the coils cthe resistance of the conductors through the several blocks areregulated to gradually increase from one end of a section of road to the other. For each block there is a graduation mark on the scale plate of the voltmeter and as each block is a mile in length, for convenience, the graduations are marked 1 mile, 2 miles, 3 miles and so on, according to the number of blocks in the section of road. The locomotive being in block T, the pointer of the voltmeter would stand at 1 mile, which would inform the engineer that the obstruction was in the next block,

or in block T If the track should be clear and the shoe S on the contact-rail c in any block a station agent at the end of the line couldsignal to the engineer by closing the switch E. By making and breaking the circuit at this point the lamps could be flashed in the cab and by usin sages could e trahsmitted. In the sanie way, the engineer. could .communicate with the station agent by opening and closing the switch 7 and thereby make and break the circuit through the bell controlled by the switch 6. Also, tele honic communication could be establishe by the" engineer in his cab opening the switch f to cut out If there should be a source of danger the main track.

a predetermined code, mes- ,the circuit of the field coils and by closing the switch f to introduce the circuit of the telephone f The telephone 6 could be brought into the circuit by closing the switch E. The telephone is not operated by the current generated by the dynamo, but de" pends on a battery such as is OrdlDallly used for such purposes. v

In Fig. 1 of the drawing a side track X is shown, which is insulated at av, 00, from the main track. A train on the siding would be insulated from the main track and could not affect the circuit through the battery B. The switch 90 for opening or closing the sidingto the main track has two wires :0 leading from the rails of the main track to the contacts a on the switch. When the lever of the switch is thrown to openthe siding to the 'main track the two contacts x are moved into engagement and the circuit through the battery B is thereby shortcircuited and the'connections between the conductors would be made the same as if the circuit had been interrupted by a train on Likewise, should a rail be broken in any block or become displaced, the circuit through the battery B of that block would be interrupted and the signals would be operated.

It is obvious that instead of track circuits arranged to indicate in which of separate blocks having individual". different resistances the obstruction is located, the track circuits can be arranged to show the condition of one or more blocks immediately in front of the train. For an instance, the rails being bonded and divided into blocks as shown in the diagram, the wire D instead of being connected in circuit through the relays continuously or with several separate blocks having different resistances is connected to run only to the relay in the next succeeding block, and all the blocks can have a uniform resistance.

could be mounted at a station on. the ground alongside of the track. In the'latter instance the field-- coils' of the dynamo would have permanent'connections with the conductorsC, D, and the action of the signals would be the same asin the cab. In this way the location of a train or otherv obstruction on the track could be ascertained at the station. e

Having thus described my invention, what I claimand desire to secure by Letters Patent is: v j

1. In an electric signal system for railways, a track divided into insulated blocks, with each rail ofcach block electrically continuous, a source of. electricity in. each block, a circuit in each block including the rails r and source of electricity adapted to be shortcircuited by an obstruction of the rails of the block, a'magnet in said circuit, conductors extending along the track with each conductor having terminals in each block, a switch. for the terminals of each conductor in eachblock normally held by the magnet in the block to close the terminals of their respective conductors, a branch wire in each block extending from one conductor to a terminal adjacent to the switch of the other conductor to contact withsaid switch when the latter is released by its magnet, a normally incomplete circuit, means for electrically connecting said normally incomplete circuit with Sfi-ld'COIldllC-tOI'S, a source of electricity in. said normally incomplete circuit,

and resistance indicating mechanism "included in said normally incompleteai it 2. In electric signal systems for railways,

conductors extending along the track and divided into blocks of different electric-resistances and forming an incomplete circuit, means-actuated by an obstruction on the track to form an electric connection between the conductors in the adjacent block, a shunt-wound dynamo mounted on the carrier movable on the track, means for elec.

source of electricity adapted to be short-circuited by an obstruction of the rails of the block, a magnet in said circuit, conductors extending along the track with each conductor having terminals in each block, a switch for the terminals of each conductor in each block normally held by the magnet in the block to close the terminals of their res )ective conductors, a branchwire in each block extending from one conductor to a terminal adjacent to the switch of the other conductor to contact with said switch when the latter is released by its magnet, a shunt-wound dynamo, means for electrically connecting the field coilsof the dynamo withsaid conductors, and resistance indicating mechanism included in thecircuit of the armature coils of said dynamo.

4. In electric signal systems for railways, a track divided into insulated blocks with each rail of each block electrically continuous, a source of electricity in each block, a circuit in each block including the rails and source of electricity and adapted to be interrupted by an obstruction on the rails of the block, conductors extending along the track, means in each block actuated by the shortcircuiting of the rail circuit of the block for electrically connecting said conductors opmeans for electrically connecting the field coils of the dynamo with said conductors, and resistance indicating mechanism and signals included in the circuit of the armature coils 'ofsaid dynamo. I

5. In an electric signal system for railways, a trackdivided into insulatedblocks with eachgi'ail of each block electrically continuous, a source of electricity in each block, a circuit in each block including the rails and source of electricity adapted to be short-circuited by an obstruction of the rails of the block, a magnet in said circuit, conductors extending along the track with each conduc tor having terminals in each block, a switch for theterminals of each conductor in each block normally held by the magnet in the block to close the terminals of their res ecadjacent to the switch of the other conductor to contact with saidswitchwhen the latter is released by its magnet, a resistance coil in said branch wire, a contact-rail adjacent to the track of each block, a wire connecting said contact-rail with one of the conductors,

a wire connecting one of the track-rails with the other conductor, a carrier movable on the track, a normally incomplete clrculton said end With the wheel traveling on the trackrail connected'with one of the conductors, a shoe on said carrier at the other end of said normally incomplete circuit 0 erating to engage the contact-rail to complete the circuit through said normally incom lete circuit and said conductors, a source of e ectricity in saidv circuit in each block including the rails and source of electricity adapted to be short-circuited by an obstruction of the: rails of the block, a magnet in said circuit, conductors extending along the track with eachconductor having terminals in each block, a switch for the terminals oi each conductor ineach carrier having an electric connection at one block normally held by the magnet in the block to close the terminals of their respective conductors, a branch wire in each block extendingfrom one conductor to a terminal adjacent to the switch of theother conductor to contactwith said switch when the latter is released. by its magnet, a resistance coil in,

. track a shunt-wound dynamo on said carrier with its field coils provided with a terminal in the wheel traveling on the track-rail connected with one of the conductors, a shoe on said carrier at the other terminal of thefield-coils 0 erating to enga e said contact-rail to comp ete the circuit t ough said field-coils and the conductors, a resistance coil interposed in the fieldcoils of the dynamo, and resistance indicating mechanism in the circuit of the armature coils of the dynamo. I

In testimony whereof I hereunto afiix my signature in-the presence of two Witnesses.

FRED LACROIX.

Witnesses: 7

CHARLES ADKINS BAKER, J. S. GOLDMANN. 

